This application claims benefit under 35 U.S.C. 371 of PCT/FR98/01223 filed Jun. 11, 1998.
1. Field of the Invention
The present invention concerns a method for continuous or discontinuous automatic analysing of samples placed in containers, such as test tubes.
2. Description of the Prior Art
So as to be analysed, the sample recipients are frequently placed in line in containers or xe2x80x9cportoirsxe2x80x9d, each containing several tubes (usually five) vertically centred inside a longitudinal vertical median plane of the container.
The containers equipped with their samples are then disposed in line on a conveyor passing into an analysis station of an analysis robot where they undergo one after the other the pipetting operations adapted to the analysis to be conducted.
This sequential processing of samples has various drawbacks:
difficulty of restarting a test or additional analysis (it is necessary to manually look for the tube in the already sampled containers),
the samples are stored at ambient temperature, which is highly prejudicial to certain unstable parameters,
the tube sorting for storing samples in the sample library or delaying tests is extremely difficult,
the urgent processing of tubes proves to be difficult owing to the fact that it is necessary to short-circuit the waiting queue.
This is why analysis robots have been suggested, said robots including a pipetting area in which the previously identified sample recipients are disposed according to a matrix distribution. According to two perpendicular co-ordinate axes, an injection and/or sampling head (pipetting head) moves above this pipetting area, the functioning of said head and the movements being controlled by a robot controlled by a processor. It is clear that by means of this disposition, it becomes possible to carry out several analysis processings in parallel and thus restart at any time. The drawback of this solution thus lies in the fact that it does not allow a continuous or semi-continuous loading of the robot: each operating sequence requires a manual loading of the pipetting area with identification of each tube, its location and the type of analysis to be carried out.
These operations, which require the presence of an operator, are relatively long and are unable to guarantee that no error occurs, especially in the identification/tube position relation.
With the aim of eliminating these drawbacks, the invention puts forward a method using an analysis robot of said type in which the sample recipients (such as the tubes), previously disposed in containers, are able to move inside the pipetting area during the phases for analysis, loading and unloading of this pipetting area, as well as the movements of containers inside the latter being carried out automatically.
So as to obtain this results, the method according the invention includes an operational cycle comprising at least the following phases:
placing the containers of sample to be analysed inside containers in which the vertically centred containers are placed in line parallel to the longitudinal axis of said containers,
a first movement of the containers one after the other along a first rectilinear path so as to bring them to the right of an access zone at the pipetting area,
a preferable automatic identification of the recipients during this first movement,
a second rectilinear movement along a path perpendicular to the first, during which the containers, placed side by side, are translation-moved and traverse straight through the pipetting area so as to reach an outlet zone situated opposite the access zone,
a third rectilinear movement zone along a path parallel to the first during, which the containers are brought one after the other from the first outlet zone to a second inlet zone at the pipetting area,
a fourth rectilinear movement along a path parallel to the second during, which the containers, which are again placed side by side parallel to the first path, are translation-moved through the pipetting area so as to reach a second outlet zone situated on the first path,
a fifth rectilinear movement along the first path so as to bring the container to the first access zone so as to restart a new cycle or to an evacuation zone of the container.
By means of these dispositions:
during the second path, each container scans a first fraction, such as a first half, of the pipetting area,
during the fourth path, each container scans a second fraction, such as the second half, of the pipetting area,
during each of these two paths, each recipient moves onto the same column of the matrix of the pipetting area.
Thus, with the aid of relatively simple sensors, it is possible to determine the position of each of the containers, the processor controlling the movements of the pipetting head being able to know at each moment, the position of each recipient in the pipetting area. Therefore, it is possible to carry out samplings or injections of products in any recipient present in the pipetting area according to a function programme of the type of analysis to be carried out, independent of the order in which the recipient has been introduced into the analysis robot.
Of course, the invention also concerns an analysis robot designed to implement the previously described method, this robot introducing on both sides of the pipetting area a first unit comprising two parallel linear conveyors designed in such a way so as to transport the containers in line orientated along the displacement axis of these conveyors, and a second unit including at least two perpendicular linear conveyors to the first two and designed so as to transport the containers, orientated perpendicular to the displacement axis of these two conveyors, into the pipetting area, the conveyors of this second unit opening into the inlet/outlet transfer zones of the two conveyors of the first unit.
The analysis robot could preferably include a device for reading the identification codes inscribed on the cylindrical walls of the tubes contained in the containers, this reading device equipping one of the linear conveyors upstream of said transfer areas of this conveyor.
Similarly, the pipetting area and more generally the inside of the analysis robot could be kept at a suitable temperature for preserving the samples.